Button and VBA Viewer running differently

Hello all, I'm new to VBA so I'm not sure how to fix this.

I have a sub where the first sheet in my workbook needs to be saved in a new workbook as values (and some number formatting) but in an .xlsx format. The way I've set it up, the code runs perfectly when I have the editor open and I run it through there, but when I assign the macro to a button and try and run it from there, it saves the workbook the code is in with a new name. I've looked online and can't see any way to stop this from happening.

I'll add the sub below

Sub Upload_Sheet()
    Dim NewWrk As Workbook
    Dim ThisWb As Workbook
    Dim ThisWbName As String
    Dim Amount As Currency
    Dim InputterName As String
        Set ThisWb = ThisWorkbook
        ThisWbName = "Agency Upload"
        'Amount is currency
        Amount = ThisWb.Sheets("Upload").Range("S9").Value
        InputterName = InputBox("Inputted by:")
        Set NewWrk = Workbooks.Add
        
            ThisWb.Sheets("Upload").Range("A1:S99999").Copy
                NewWrk.Sheets("Sheet1").Range("A1:S99999").PasteSpecial Paste:=xlPasteValues, Transpose:=False
            ThisWb.Sheets("Upload").Range("E1:E99999").Copy
                NewWrk.Sheets("Sheet1").Range("E1:E99999").PasteSpecial Paste:=xlPasteValuesAndNumberFormats, Transpose:=False
            ThisWb.Sheets("Upload").Range("I1:I99999").Copy
                NewWrk.Sheets("Sheet1").Range("I1:I99999").PasteSpecial Paste:=xlPasteValuesAndNumberFormats, Transpose:=False
            
                    NewWrk.Activate
                    NewWrk.Application.Dialogs(xlDialogSaveAs).Show (ThisWbName & " £" & Amount & " " & InputterName & ".xlsx")
                    NewWrk.Close
                        
            MsgBox "Upload sheet saved"
End Sub